At present, the location of any points of interest on an aircraft external surface is typically made by human assessment. This involves taking measurements from known reference positions such as stations or frames, body lines, water lines, stringers, production joints, access panels, or specific structural features. This can be particularly difficult on large modern aircraft that have expanses of featureless surfaces. For example, the surface of a modern composite aircraft will not have the vast number of rivet lines visible on traditional metallic aircraft.
Location referencing is usually made from two-dimensional drawings (found within aircraft manuals) to establish the known datums from which the measurements are made. Human error sometimes means that the measured locations are not accurate and any subsequent engineering follow up action or further assessment is delayed, or needs to be assessed differently to that initially anticipated. The locations of any points of interest which are found to be damage are recorded on a document generally known as the ‘Dent & Buckle’ chart.
U.S. Pat. No. 5,828,969 describes an aircraft maintenance control process, which involves photographing a damaged component with a digital camera, downloading the image data to a database to produce a record, visually assessing the damage, and annotating the electronic record with instructions for repair. Whilst this process produces a more accessible, comprehensive record, it does not address the problems of human error in accurately recording the damage location.